Preventing random number duplicates??

[santafeguy]

I am trying to generate 5 unique random numbers, but am finding that my method(s) every once in a while will create duplicate numbers. In truth, I expected this to happen, but my attempts at preventing this have failed. This is my partial code:

randNum_1 = 1 + (arc4random() % 59);
randNum_2 = 1 + (arc4random() % 59);

if (randNum_2 == randNum_1) {
randNum_2 = 1 + (arc4random() & 59);
}

It's obvious that there is nothing to prevent the second randNum_2 from being a duplicate of randNum_1 again and this is my problem. I have tried the following code with no success:

while ( randNum_2 == randNum_1) {
randNum_2 = 1 + (arc4random() & 59);
}

The while stmt generated a new randNum_2 whether it was necessary or not.

Any suggestions or comments will be greatly appreciated. Thanks.

[lgehrig1]

First, is there any reason why you're doing a bitwise AND with 59 when the random numbers are equal?

Second, what do you mean the while generated a new random number "whether it was necessary or not"? Did you actually breakpoint or log? Because if it's going into the while when the two values are different then you'd likely have an infinite loop, and this isn't the case is it? Make sure you didn't add an extra semi-colon just after your closing paren on the while.